Weather resisting material



'Patented Feb. 27,

UNITED STATES PATENT OFFICE 1,948,979 WEATHER BESISTING MATERIAL PhilipW. Codwise, Kenmore, N. Y., assignorto Y Certain-Iced ProductsCorporation, New York, N. Y., a corporation of Maryland No Drawing.Application June 2'7, 1932 Serial No. 619,522

12 Claims.

This invention relates to covering material and especially to coveringmaterial having weatherproofing or waterproofing qualities. Moreparticularly the invention relates to prepared roof- Prepared roofing ascommonly understood comprises a sheet of fibrous material which has beenfelted, the felted sheet being saturated with a mastic or bituminousmaterial. A well known lo form of this material is made by using as abase material aso-called wool felt which is made of waste in the form ofrags which have been reduced to the constituent fibres by well knownprocesses. With such wool felts for roofing purposes frequentlyadmixtures of papers or paper pulps or other fibrous materials have beenused in order to lessen the cost or modify the felting characteristics.

As the mastic material, asphalt has commonly been used of suchconsistency as to provide for saturation of the felt with the asphalt toproduce a product commonly known as saturated felt. To produce preparedroofing, saturated felt is commonly coated with an applied coating orlayer of asphalt upon one or both sur- Sid faces of the sheet. Toproduce mineral surfaced roofing, as is well known, granular slate orother granular mineral material is applied upon the asphalt coating soas to adhere thereto.

In felts used prior to my'invention certain fibrous materials, eitheralone or in mixtures with rags, have been used for the purpose ofincreasing the amount of the mastic or bituminous material which couldbe absorbed by the felt. l'nall such roofing products it is desirablethat the felt shall carry as much of the saturant as possible, thusreducing the amount of felt necessary to carry a givenamount of thewaterproofing mas tic or bituminous material. Felts which have beenproposed prior to the present invention have included those which haveutilized resinous wood fibres, such as yellow southern pine fibresproduced in a chemical process. Also in my prior Patents Nos. 1,857,432and 1,857.433, dated May 1c, 1932, I have described a felt utilizingbundles of fibres to produce the desired porous or open structure of thefelt necessary for high saturat ing capacity. The fibre used accordingto said patent also is prepared by a chemical process using caustic sodain which the separation of the individual fibres is incomplete, thusproducing the. fibre bundles and utilizing the absorbent character ofthe fibre bundles as well as of the felted form of said bundles.

According to the present invention I have discovered that the desirablehigh absorptive quality of a felt for roofing purposes and the highcapacity of such a felt for a saturant such as a bituminous material,for example, asphalt, may be producedby using a felt comprising orcontaining a substantial amount of the fibres of wood which are producedby the so-called soda pulp" process. Such a felt may be made in theusual manner of producing felts on a paper machine or by other feltingprocess and I have discovered that when so felted the absorptivecapacity of such a felt is much higher than that obtained previous to myinvention by the use of individual wood fibres and that this absorptivecapacity, that is, the saturation capacity of the felt, is nearlyequivalent to that which is obtained by the use of rags alone andexceeds that of the usual rag fibre combinations with wastepapers as iscommon practice.

The process of manufacturing soda pulp depends upon the solvent power ofcaustic soda for certain constituents of the wood, converting them intosoluble salts of soda. The reactions are very complicated but thedegradation of the woody constituents is in. general greater than thatwhich occurs for the same constituents'when the wood is treated by theso-called sulphite process. in. the soda pulp process the wood is barkedand chipped as is customary in various chemical pulping processes. It isthen furnished to a digester together with the proper amount of causticsoda solution and with careful regulation of the total amount of waterintroduced. The time required for a cock. is 5 to 8 hours and the steampressure is usually between 100 pounds and 120 pounds per square inch.At completion of the cool: the pulp is blown into pit, washed, and, ifwhite pulp is desired, is then bleached. In order to produce soda pulp18% to oi caustic soda (NaOli) based on dry weight of the wood isrequired.

The known characteristics which in general distinguish soda pulse from,other chemical pulps are its softness and. bulking properties. T. havealso discovered that said pulps, perhaps due the softness and bulkingproperties, have a high absorptive capacity for asphalt and bituminoussaturants. the theory that the destruction or degradation of the woodyconstituents mentioned above has gone so far in the manufacture of thisparticular type of wood pulp as to open upthe cell structure, thusswelling the individual fibres and rendering them highly absorbent toasphalt or bituminous saturants. This absorptive quality is greater thanthat possessed by individual fibres prepared by I account for thischaracteristic on other processes. While papers of various degrees ofcompactness of the felting have been known.

the treatment with caustic soda which aifects the According to thestatement in the patent to Ed":

fibres themselves both as to their cell structure and as to swelling ofthe individual fibres, is more highly absorbent to asphalt and similarbituminous saturants than other paper fibres. I propose to use fibreswhich are so treated according to commercial practice as to retainsufficient strength of the fibre while securing the opened or swelledcondition of the fibre for the purpose of obtaining the absorptivequality.

Of the wood fibres whichhave been used, I am aware that southern yellowpine rich in resinous substances has been treated in a chemical process.

ward J. Schroeder, 1,188,495, in a chemical process of producing woodpulp southern resinous woods containing relatively large resin ductshave been treated so as substantially to empty these ducts of resin. Theproduct is designated in said patent as chemicalresinous wood fibre orchemical fibre of southern yellow pine. While the fibrous productsuggested in the patent to Schroeder was intended to be used for roofingfelts. to replace wool felt, the fibres and the felt made from saidfibres are a different product from that which I propose to utilize inmy invention.

' These fibres do not have the soft character of the fibres of soda pulpand are not swelled as are the soda pulp fibres. The fibres which Iutilize in my invention .are those whichresult from the treatment ofwood with strong solutions of caustic soda which open up thecellstructure in the woods which are so treated and do not merely remove theresinous material from the ducts.

Moreover, for the most part soda pulp is made from non-resinous woods orthe hard woods such as poplar, gum, maple and other woods of relativelyshort fibres. The process of treatment contributes to the characteristicsoftness of the pulp and to the felting quality which assists in givingthe felt a high absorptive capacity.

My invention therefore consists in the discovcry of the high absorptivecapacity of soda pulp and of soda pulp felts for mastic or bituminousmaterials, particularly bituminous saturants, such as asphalt, which areused in prepared roofing. My invention in its practical form resides inthe combination with a felt containing soda pulp of such a saturant,particularly asphalt.

I have found that the advantage afforded by the use of soda pulp inroofing felt may be obtained to a considerable degree when othermaterials, such as paper or paper pulps and other fibrous materials areadmixed with the soda pulp. Moreover, while in some cases felts made ofrags may have higher 'absorptive capacity than felts made of soda pulpalone or of mixtures of soda pulp and rags, nevertheless the admixtureof the soda pulp with the fibre obtained from rags produces a felt ofmuch higher absorptive capacity and one capable of saturating morerapidly than mined by tests the amount of asphalt which will be absorbedby the felt which I utilize in my invention and also I have determinedthe relative rate of absorption of saturating materials of the sodapulpfelt as compared with other felts used particularly in the manufactureof prepared roofing. A felt of usual thickness consisting of 100% sodapulp was found to saturate readily with asphalt and to take up 177% ofits weight in asphalt. This felt showed a kerosene saturation test of195% and an oil penetration test of -10 seconds. These tests comparevery favorably with those obtained with commercial rag felt ofequivalent thickness.

To show the comparison between mixtures of rags and soda pulp andmixtures of rags and paper as commonly used tests were made with thefollowing results:

50%soda 50%mixed 50%newspul and papers and papers and Caliper .045".047"; .047". Kerosene. 159% 111 147%. Oil netration 10sec-.- 2sec.-67m. Astp u)lt saturation (labora- 132% 104% 118%.

ory

In connection with these tests it is to be noted that the rate of oilpenetration is a measure of the rapidity with which the felt absorbs thesaturant, which quality in roofing felts is highly important, as feltswhich rapidly absorb the saturant may be treated more quickly in theprocess of manufacturing the roofing than those which require a longertime-for the penetration of the saturant into the felt. It will be notedthat the soda pulp accelerates the penetration when substituted for thepapers usually used in mixtures. It will also be clear that a highpercentage of saturation by the asphalt is obtained with the soda pulpas compared with pulps of ordinary mixtures using rags and paper. As hasbeen explained above, this is a valuable feature of a felt for roofingpurposes, because a larger amount of the weatherproofing orwaterproofing material may be carried for a given thickness of fin ishedroofing or a thicker, heavier and more durable roofing may be producedwith the same weight of felt as is now used for the normal product.

What I claim is:

1. As an article of manufacture a weather resisting material comprisinga sheet of felt containing a substantial amount of soda pulp, and awater proofing saturant impregnating said felt.

2. As anarticle of manufacture a weather resisting material comprising asheet of felt composed for the most part of soda pulp and saturated withasphalt.

3. As an article of manufacture a weather resisting material comprisinga sheet of felt containing a substantial amount of the wood fibersresulting from the process of treating wood with caustic soda to produceindividual fibers known as soda pulp, and a bituminous saturantimpregnating said felt.

4. A roofing material comprising a base in the form of a sheet of feltedsoda pulp wood fibers, and asphalt saturating said felt sheet.

5. A roofing material comprising a sheet of felted fibers containing atleast 25% of soda pulp wood fibers and saturated with asphalt.

6. As an article of manufacture a weather resisting material comprisinga sheet of felt containing soda pulp, rag fibers, and a water proofingsaturant impregnating said felt.

7. As an article of manufacture a weather resisting material comprisinga sheet of felt contaming a. substantial eimount of individual cellulosefibers substantial y unbound (for the most part) by naturalincrustations soluble in strong solutions of caustic alkali and havingtheir cell structure opened and swelled by said alkali treatment butsubstantially retaining the integrity of v the individual fibers, and awaterproofing saturant impregnating said felt.

' 8. As an article of manufacture, a weather resisting materialcomprising a sheet of .felt containing soda pulp, paper stock, and awater proof saturant impregnating said felt.

9. As an article of manufacture a sheet of felted cellulose fibers whichare the proluct of "a process using caustic soda in strong watersolution at high temperature and pressure for producing a primauv pulpfrom wood. said fibers being substantially individual and substantiallyfreefrom the materials binding them together when in the wood and as aresult of said process being soft and of such opencell structure asmarkedly to increase the bulk of the individual fibers with respect totheir bulk when in the wood but substantially retaining the integrity ofthe individual fibers, and a water proofing saturant claim 9 in whichthe fibers comprise a substantial amount of fibers of gum wood.

PHILIP W. CODWISE.

